baxter



l l i Patented June '7, 1904.

PATENT OFFICE.

ARTHUR wisnxrnn, jor LONDON, ENGLAND.

PROOES S OF'lVlAKlNG FlREPROOFING SOLUTIONS.

sPEc'IFIcATIoN forming partof Letters Patent No. 761,870, dated June 7, 1904.

Application filed March 23,1903.

- post-ofliceaddress is Ardingley House, Par- -sons Green, London, England,) have invented certain new and useful Improvements Relating to Processes forthe Manufacture of Fireproofing Solutions, (for which I have applied fora 0 patent in Great Britain on the th day of September, 1902, and in Grermanyon the 2d of March, 1903,) of which the follow ing is a specificatiom The usual method of fireproofing wood and rs other organic matter consists in impregnating it with a solution of suitable saltssuch as, for.

; instance, sulfateofammonia. This salt, howevgr, has defects, inasmuch asit is hygroscopic articles treated with it absorb water and cause and attacks metals, in consequence of which ,iron and steel to rust. Numerous other solu-- ;tions have been tried or proposed which are i satisfactory for the purpose in some respects, bu t the drawbacks accompanyingtheir use outi5 weigh the udvantag In some cases the wood is-subjected to two impregnations, the first serving to force into the pores of the wood a suitable salt, which pores are subsequently closed by the second impregnation. This 3 method is,however', unnecessarily expensive.

Silicate of soda and of potash will also resist hent;-and--are therefore used for the maniacture of fireproof paint,butthelr-aqueousso;

lutions will notreinai'ifliquid-longenouglilfi 3S render them suitable for the impregnation of wood. A mixture of bisulfatc of ammonia in aqueous solutionwitha solution of an alkalisilicate to be used in the shape of small jets has been recommended for the extinction of fire,

4 but would not be suitable as a solution for the may be avoided and an efiicient and cheap fireprooiingsolution obtained which is comparatively non-hygroscop c and has no corrosive action on metals by mixing a solution of sulfate of ammonia with asolutiou of silicates of" 5 soda and of potash prepared in the manner Serial No. 149,151. (No specimens-l hereinafter described and neutralizing the mixture with an acid. The mixture obtained as described Will'remain liquid for an indeli- R nite length of time, so that 1t can be used repeatedly for the impregnation of wood, and it combines high efiiciency with cheapuess.

Two and three-eighths parts, by weight, of silica are fused together with live and threefourths parts of potassium carbonate and four parts of sodium carbonate. After the escape of gases has ceased the fused, mass ispohrect into fifty-two and one-fourtli iiarts of water;

'and boiled for about thirty minutes and then allowed to cool and filtered. A separate solution is made up of thirteen and three-fourths parts of sulfate of ammonia in scventy two I parts of water. The two solutions thus pre-- pared are mixed together in equal quantities and sulfuric acid is then added until the solution has a slightly acid reaction when tested with litmus-paper. The strength of the impregnating solution and the relative'quautities of its constituents may be varied, according to the nature of the material to be treated with it, but the solution of silica added to th 'e ammonium sulfate should natethat is to say, more than is required for converting the silica intoalkali silicate.

The method of impregnation may be the same as that adopted with other impregnating solutions.

W hat I claim is j'..'.1;- --'ihe-.pr ocess for obtaining a ire-proofing solution, which consists in fusing sodium and potassium carbonate together with, silica, dissolving the fused mass in water, mixing the solution with fan aqueous solution or annnonium sulfate, andneutralizing the mixture, substantially as described and for the purpose specified.

.2- The process for obtaining a fireprooling solution, which consists in fusing silicategethcr with an excess of alkali carbonate, dissolving the fused mass in water, mixing the solutionwith a solution of ammonia sulfate in water, and neutralizing the mixture, substantially as described,

" "-"3'.'- The process for the inanufactu re of a fireprooling solution which consists in fusing silica together with sodiumearbonate and potassium In witness whereof I have hereunto signed carbonate npproxiumtely in the proportions my name in the presence of two subscribing described, dissolving the fused mass in hot witnesses. 7

water and mixing the solution with an aqueous ARTHUR W BAXTER. 5 solution of mmnonium sulfate approximately Witnesses:

in the proportion described and neutralizing J. W E'L'IEH,

the mixture with sulfuric acid. \VAL'LER 1C. Roar-rm. 

